package linkedlist.passed;

/**
 * @author xyyi
 *
 */
public class AddTwoNumbers {
	/**
	You are given two linked lists representing two non-negative numbers. 
	The digits are stored in reverse order and each of their nodes contain a single digit. 
	Add the two numbers and return it as a linked list.

	Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
	Output: 7 -> 0 -> 8
	 */
	/**
	 * 
	 */
	public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
		// Start typing your Java solution below
		// DO NOT write main() function
		//		if (l1 == null)
		//			return l2;
		//		if (l2 == null)
		//			return l1;

		ListNode dummyNode = new ListNode(-1);
		ListNode currNode = dummyNode;
		int carry = 0;
		while (l1 != null || l2 != null || carry != 0) {
			int sum = 0;
			if (l1 != null) {
				sum = sum + l1.val;
				l1 = l1.next;
			}
			if (l2 != null) {
				sum = sum + l2.val;
				l2 = l2.next;
			}
			sum = sum + carry;
			carry = sum / 10;
			sum = sum % 10;
			currNode.next = new ListNode(sum);
			currNode = currNode.next;
		}

		return dummyNode.next;
	}

	/**
	 * Definition for singly-linked list.
	 */
	public class ListNode {
		int val;
		ListNode next;

		ListNode(int x) {
			val = x;
			next = null;
		}
	}

	public AddTwoNumbers() {
		// TODO Auto-generated constructor stub
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub

	}

}
